In Shadow. By Trish Janeshutz. Ballantine. $3.50.

Denise Markham, a brilliant, beautiful young chemist -- and psychic -- is murdered at a Miami university. As detective John Conway delves into her life, he discovers that Markham had developed a drug akin to cocaine and LSD that augmented her psychic powers.

Without proper testing, she had been administering the substance to friends who bankrolled her research, and now the drug is eating up the users` livers and causing psychotic behavior. Adding to the turmoil, the killer is stalking the only witness to the murder and Conway has fallen in love with a professor he met on the case.

Although Janeshutz has blind spots (e.g., a proclivity for hothouse metaphors and an assumption that all men are SOBs), she is a whiz with characters, suspense and the South Florida setting. Overall, In Shadow is an enthralling, violent and seductive novel.

CAUGHT. BY JANE SCHWARTZ. AVAILABLE PRESS/BALLANTINE. $5.95.

The protagonist of this taut, direct novel is Louie, a 10-year-old girl living in the Brooklyn of the late `50s. Outwardly tough but unsure of herself, she becomes a ``chaser,`` or apprentice, for champion pigeon-flyer Casey, an older man whose family life and work life are in disarray.

While Casey teaches Louie ``flying`` and how to care for the pigeons, the two become friends. Louie`s family and teachers question her devotion to the pigeons, while other ``birders`` react with amusement to Casey`s girl ``chaser.`` Eventually, however, she earns their respect.

By the end of the tale, when her family decides to move to suburbia, Louie has matured greatly and the outlines of young womanhood are apparent. In addition, pigeon-flying has helped her survive a brutish street culture and the murder of a friend.

ALONE. BY BEVERLY FARMER. PENGUIN. $4.95.

Set in Australia, this is a painfully sensuous novel of a young woman`s obsession with violent love and violent death. Her world is a nightmarish still-life, composed of a spider-infested boarding house, a dank cafe and a remote Gothic university, where her lesbian lover lives.

The book is populated by grotesque caricatures of rotting humanity that mirror the woman`s anguish over her lover`s absence.

Farmer possesses a distinct gift for exaggerating isolated moments of human passion -- then returning, at the right moment, to the ugly yet poetic reality of her characters` lives.

NUNS AND MOTHERS. BY AILEEN LA TOURETTE. VIRAGO PRESS. $5.95.

Helena Carnet and Georgia Manion were once schoolgirl chums at chaste Stella Maris Academy. Twenty years later, on a sort of lesbian honeymoon, they visit the scenes of Helena`s childhood in Coldwick, N.J.

The plot develops through a series of dialogue games of ``remember,`` in which childhood dynamics are confessed, repossessed and eventually absolved by the women`s adult sensibilities.

La Tourette`s writing has occasional gusts of power, and the novel is well- structured. But the monologue of Helena`s family reminiscences ultimately becomes an imposition on Georgia -- and on the reader.

JUDGMENT BY FIRE. BY THOMAS PHILO. BANTAM. $3.95.

After finishing some hurried, last-minute translations of Livy, classics major Bob Dannon returns home to Detroit from school in California. He discovers that a furnace explosion in the night has wiped out his family.

Suspecting foul play, Bob pokes into his father`s murky past and uncovers some not-so-friendly alliances dating back to World War II. Exploring further -- New York and the south of France -- he finds that the enmity once directed at his father is now focused on him. By keeping a cool head (to relax, he conjugates Latin verbs), Bob manages to escape the fate of the rest of his family.

Lacking any real style, this novel leans heavily on a plot that, in the end, can`t quite support it.